Due to the flammable and explosive characteristics of hydrogen gas, the safe operation of the equipment is particularly important. Any minor negligence may lead to serious accidents in the process of hydrogen production so great attention should be paid to the safety of each equipment in the production line. In this paper, the abnormal leakage failure of the TP321 stainless steel pipe that conveyed medium temperature shifting gas in a petrochemical factory was systematically studied. In order to find out the causes of the failure, the operating conditions, the material qualities of the failed pipe, the macroscopic and microscopic morphologies of the fracture, and the gas flow velocities were comprehensively analyzed. The results showed that the root causes of the failure were processing stripes and incomplete passivation film on the inner surface of the pipe due to inappropriate surface processing, which then initiated pitting corrosion and intergranular corrosion. Besides, the additional assembly stress between the pipe and fitting also produced larger longitudinal tensile stress, facilitating the initiation of stress corrosion cracking. Under the interaction of pitting corrosion, intergranular corrosion and stress corrosion cracking, the pipe leakage finally happened during its service. Based on these failure causes, some feasible countermeasures were then put forward for leakage prevention of similar structures or equipment in hydrogen production industry.

由于氢气具有易燃易爆特性，因此设备的安全运行尤为重要。任何轻微的疏忽都可能导致制氢过程中的严重事故，因此应特别注意生产线中每台设备的安全性。本文系统地研究了石化工厂输送中温变换气体的TP321不锈钢管的异常泄漏故障。为了找出故障的原因，对工作条件，故障管道的材料质量，裂缝的宏观和微观形态以及气体流速进行了综合分析。结果表明，失效的根本原因是由于不适当的表面处理而在管子的内表面加工了条纹和钝化膜不完整，从而引发了点蚀和晶间腐蚀。此外，管道和配件之间的附加装配应力也产生了较大的纵向拉应力，从而促进了应力腐蚀裂纹的产生。在点蚀，晶间腐蚀和应力腐蚀开裂的共同作用下，管道在使用过程中最终发生泄漏。针对这些故障原因，针对制氢行业类似结构或设备的泄漏提出了一些可行的对策。然后开始点蚀和晶间腐蚀。此外，管道和配件之间的附加装配应力也产生了较大的纵向拉应力，从而促进了应力腐蚀裂纹的产生。在点蚀，晶间腐蚀和应力腐蚀开裂的共同作用下，管道在使用过程中最终发生泄漏。针对这些故障原因，针对制氢行业类似结构或设备的泄漏提出了一些可行的对策。然后开始点蚀和晶间腐蚀。此外，管道和配件之间的附加装配应力也产生了较大的纵向拉应力，从而促进了应力腐蚀裂纹的产生。在点蚀，晶间腐蚀和应力腐蚀开裂的共同作用下，管道在使用过程中最终发生泄漏。针对这些故障原因，针对制氢行业类似结构或设备的泄漏提出了一些可行的对策。沿晶间腐蚀和应力腐蚀开裂，管道在使用过程中最终发生泄漏。针对这些故障原因，针对制氢行业类似结构或设备的泄漏提出了一些可行的对策。沿晶间腐蚀和应力腐蚀开裂，管道在使用过程中最终发生泄漏。针对这些故障原因，针对制氢行业类似结构或设备的泄漏提出了一些可行的对策。